Electrical condenser



, ,atented Dec."4, 1934 vPATENT 1 OFFICE I UNITED Ns'iuafras Application May 31, 1930, Serial No. 458,078

l 6 Claims.

y This invention relates to the constructon of a variable -electrical condenser of the type used in radio receiving sets. In Cramer Patent 1,800,719, issued April 14, 1931, there is shown and described b ways and means for constructing a multiple unit or gang condenser.

Our present invention includes a special application of the means for mounting'the rotor shaft as vset forth in said patent. The present invention also includes additional improvements in the construction-of condensers, and for utilization in gangs.

It is one of the objects of our invention to provide an improved form of unitconstruction of a condenserhaving a minimum number of parts, and therefore a unit which is cheap to manufacture,

Another object of our invention is to provide an improved form lof mounting the movable elements or plates on the frame.

A still further objectA of our invention is to provide a construction for an individual unit condenser which lends itself to the economical manufacture of gang condensers.

Other objects will be discerned after reading the specification taken in connection with the annexed drawing, wherein:.

Figure 1 is a plan view ofthe individual or unit condenser ready for assembly into agang. 30 Figure 2 is a view of the end of the condenser,

loolging from left to right, in Figure 1.

Figure 3 is a part-sectional view through the shaft support'and bearing means.

-Figure 4 is a plan view of a three-gang con-` denser using the units shown in Figures 1 and 2 mounted on a common mounting plate, the end view of one of the condensers being indicated by dotted lines behind the mounting plate, while the other two are merely indicated in outline.

Figure 5 is a front elevation of the gang condenser shown in Figure 4. j

, Figure 6 isa plany view of a modified form of bearing plate used in the construction of vthe individualunit condenser.

Figure 'I isy a side view of Figure 6 partly in section.

v Figure 8 is a view through a part` of the condenser frame on the line 8-8 of Figure 1, without any of the condenser parts being mounted thereon. l

Figure 9 is a section on line 9-f-9 ofFigure'lO. Figure 10 is a plan view of a modified form of bearing plate.

Referring now to the details, wherein like numbers refer to corresponding parts in the various stantially at right angles to each other.

views, the individual condenser unit is carried on an L-shaped frame having portions 1 and 2 sub- Preferably, this frame is made from sheet metal and has a pair of upturned lugs 3 and 41oppositely 60 spaced on the portion 2 of the frame.

The lug 4 is much longer than lug 3 and lhas an extended arm 5 at one side supporting a porn tion 6, the purpose of which will be later referred to. 4Attached to the lugs 3 and 4, asby means of 05 screws 7, are insulators 8. The other ends of the insulators 8 are fastened as by screws 9,' to

, tie bars 10 carrying a group of stator pla-tes 1l.

Cooperating with the stator group of plates, are series of` plates 12 comprising the rotor, a tie bar 13 being preferably used at one end of the rotor plates to securely maintain them in position.

The rotor plates are carried on a sleeve 14 which is fastened to a shaft 15 in any satisfactory man- 75' ner as by set screws 16.

The manner of supporting the rotor shaft is one of the features of this application, and as illustrated, the metal of the portion l of the frame is formed outwardly at 17 to provide a race-v 80 way for anti-friction bearing members such as the balls 18. The shaft 15 is provided with acomplementary race-way 19,and closely adjacent the race-way 19, is another race-way .20, in which preferably similar-sized balls 18 are positioned, being held in place by a complementary raceway formed in the plate 21 which is attached to the frameportion 1 in any satisfactory manner 'as by screws 22. The plate 21 may be' considerablythinner and more resilient than thev frame member to which itisY attached, and may be con-V structed as-shownin vFiguresf and '1, wherein 'a plurality of lugs 234 are punched a slight distance inwardly from the plate'21 so as to provide an automatic take-up in the bearing just described to overcome any inaccuracies in the manu facture of the race-ways either in the' vshaft or the frame portion 1, or plate 21, or in all of them.

As another adjunct to the condenser,.which is sometimes asked for by radio set-manufactur-- ers, is an auxiliary or trimming condenser which comprises a plate 24 attached to the insulator '8 by the same screws 9 used for` holding the stator tie plate 10 to said insulator. The screws 9 also serve to connect the plate 24 in electrical contact with the stator group of plates through the medium of the tie bar 10.A The plate 24 is provided with a terminal 25 for making a connection thereto.

PQSitiQned, in a threaded hole 26 in the lug 6, 110

'of a very small capacity condenser.

is an adjustment screw 27 which is insulated from the plate 24 by means of an insulator 28, whereby the plate 24 and the lug 6 form the two elements By the adjustment of the screw 27, the capacity of this small trimming condenser may be varied slightly, whereby the entire capacity of the unit may also be varied slightly, vwhich is sometimes desired when the condenser is used in a gang and it is required that the capacity of each circuit at the zero setting be made substantially the same.

While we have shown the auxiliary condenser mounted on the left-hand side of the unit condenser as shown in Figure 1, it may be mounted on either side by a suitable arrangement of the lugs, and as shown in Figure 4, the auxiliary condenser is mounted on the opposite side of the unit condenser than shown in Figure 1.

In Figures 4 and 5, three of the individual units as heretofore described, are shown mounted on a mounting plate 29 in any satisfactory manner as by screws 30, three being illustrated. In the mounting of the unit condensers asshown in Figures 4 and 5, the condenser is turned ninety degrees to the left from that shown in Figure 1, and as' has been stated, the auxiliary condenser is placed on the end, which will bring the adjustment screw 27 into the position shown in Figure 4.

In order to get at the adjustingv screw 27, holes 31 are provided in the plate 29 whereby a screwdriver may be passed through the holes 31.

In this three-gang condenser as illustrated in Figures 4 and 5, the centrally located condenser has its shaft 15 provided with a double-groove pulley 32 to receive belts 33 and 34 cooperating with pulleys 35 and 36 on the shafts of the other two condensers, the shafts of which are preferably shorter than the centrally located condenser which is the only one which receives a dial whereby all the condensers may be tuned with one movement of the dial.

In order to hold the rotors in any given set position, some special means must be provided and this may takethe form of resilient spring members 37 which engage the respective belts 33 and 34, these resilient members being mounted on the plate 29 in any satisfactory manner as by screw 38. However, in place of the special means just described for holding the condensers in set position, we may utilize other forms of friction devices, such as a modified form as that shown in the application previously referred to.

By constructing condensers in the manner just described, a large number of units having a short rotor shaft may be carried in stock, and a much smaller number of condenser' units having a. shaft as shown in Figure 1, and gang condensers can be readily made up by` bringing together one of the condenser units having a long shaft to the rotor to receive the dial and as many of the condenser units having short shafts as are desired to make up the gang. 'This brings about an economical method of manufacture, including a material saving in the amount of stock of raw material and finished condensers.

In Figures 9 and 10, there is shown a form of bearing plate similar to that shownl in Figures 6 and 7, but provided with lugs or pins 39 which are adapted to be forced into cooperating holes in frame 1 to hold the bearing plate 21 in position while the screws 22 are being put in. In place of the pins 39 as shown, lugs may be forced out of the plate at the same time the lugs 23 are formed.

Other details may also be varied without departing from the spirit of our invention ory the scope of the'appended claims.

Having thus described our invention, what we claim is:

1. For a variable electrical apparatus having a frame supporting fixed and movable cooperating parts, the latter of which includes a shaft, said shaft support comprising a plurality of adjacently arranged raceways in the shaft, and complementary raceways therefor, one raceway being formed integral with the support and the other being formed in a plate attached to the support, and anti-friction bearing members positioned in said raceways. l j

2. For a variable electrical apparatus having a frame supporting fixed andmovable cooperating parts, the latter of which includes a shaft, said shaft support comprising a pair of closely arranged parallel raceways in the shaft, and comple'` mentary raceways carried by the frame with antifriction bearings in saidraceways.

3. For a mechanical apparatus having a frame supporting xed and movable cooperating parts,

support comprising a pair of closely arranged parallel raceways in the shaft, complementary raceways carried by the frame with anti-friction bearings in said raceways, and means for compensating for inaccuracies in the manufacture of said raceways. l

4. For a mechanical apparatus having a frame supporting fixed and movable cooperating parts, the latter of 4which includes a shaft, said shaft support comprising a pair of closely arranged parallel raceways in the shaft, said frame having a complementary raceway for oneof the shaft raceways, a bearing plate attached to the frame and having a complementary raceway for the other of said shaft raceways, a part of said bearing plate being formed to provide a yielding surface 'for the purpose described, and anti-friction bearings in said raceways.

5. For a mechanical apparatus having a frame supporting xed and movable cooperating parts, the latter of which includes a shaft, said shaft support comprising a pair of closely arranged parallel raceways in the shaft, said frame having a complementary raceway for one of the shaft raceways, a bearing plate attached to the frame and having a complementary raceway for the other of said shaft raceways, cooperating means on the frame and bearing plate to hold the latter in position while the permanent fastening means are being put in place.

6. For a mechanical apparatus having a frame supporting fixed and movable cooperating parts, the latter of which includes a shaft, said shaft support comprising a pair of closely arranged parallel raceways in the shaft, said frame having a complementary raceway for one of the shaft raceways, a bearing plate attached to the frame and having a complementary raceway for the other of said shaft raceways, means for compensating for inaccuracies in the manufacture of said raceways, and cooperating means on the frame and bearing plate to hold'the latter in position while the permanent fastening means are being putin place.

STANLEY S. GRANIER. EMIL D. KOEPPING.

the latter of which includes a shaft, said shaft I 

